In general, seat covers have ventilation holes and are widely used not only on the backrests of vehicle seats, but also on domestic furniture.
Such covers are generally made of natural leather or synthetic leather.
In addition, ventilation holes in a seat cover are formed by punching the seat cover using a punching machine (or punching system).
An invention for forming ventilation holes in a seat cover using punching pins of a punching machine has been filed in the Korean Intellectual Property Office (KIPO).
Korean Patent Application No. 10-2009-0043104, dated on May 18, 2009 (titled: “PUNCHING APPARATUS FOR LEATHER”), filed in the KIPO will be described with reference to FIG. 1. According to the claims of this document, a punching machine for leather includes: a table 10 including a work board 12, a stand 11 provided above the work board 12, and four legs 13 supporting the lower portion of the work board 12; a punching unit 20 including an upwardly and downwardly-movable cylinder 21 disposed below and connected to the stand 11, and a punching pin 22 being moved up and down by the operation of the cylinder 21; a geared leather feed unit 30 including a rotary moving member 32 having grooves 31 formed in the outer circumference thereof and configured to rotate in one direction to move a sheet of leather placed thereon, an elastic pin 33 elastically entering the grooves 31 of the rotary moving member 32, and a cylinder 34 engaged with the elastic pin 33 to move the elastic pin 33 back and forth; and a support bearing 40 located above the rotary moving member 32 of the geared leather feed unit 30 and axially disposed on a support shaft 41 to support the upper portion of the sheet of leather located above the rotary moving member 32. A guide 14 is further provided in front of the stand 11 of the table 10, an up/down limiter 23 is further provided on a portion of the guide 14 to be electrically connected to the cylinder 21, and a contact 24 is further provided adjacently to one side of the punching pin 22 of the punching unit 20 to be guided up and down by the guide 13 provided in front of the stand 11 to come into contact with the up/down limiter 23.
However, the punching machine for leather of the related art fails to punch ventilation holes in a leather sheet of furniture (or a sheet cover) according to a design desired by the user in a short time, which is problematic.
Accordingly, problems of significantly low productivity and workability have resulted.